A vehicle electric power steering system can utilize a monitoring system that monitors a motor shaft position in the electric power steering system. The monitoring system, however, is turned off when the ignition of the vehicle is off (i.e., an ignition off state of the vehicle). Accordingly, if a vehicle operator turns the steering wheel (i.e., handwheel) during the ignition off state, when the monitoring system is subsequently turned on during an ignition on state, the monitoring system may not be able to accurately determine an absolute rotational position of the motor shaft.
Accordingly, it is desirable to provide a system and a method for determining an absolute rotational position of a rotatable shaft of a motor in an electric power steering system during an ignition off state of the vehicle. While a system that determines absolute rotational position in an electric power steering system during an ignition off state of the vehicle can be effective by periodically checking the rotatable shaft position of the motor, abrupt steering wheel motion can be difficult to detect when monitoring is performed on a fixed periodic basis.